脑胶质瘤P16基因分子病理研究

目的：检测１５例脑胶质瘤中Ｐ１６基因及蛋白的存在状况。方法：用复合ＰＣＲ和免疫组织化学技术检测１５例脑胶质瘤。结果：显示Ｐ１６基因与Ｐ１６蛋白丢失率均为６０．０％（９／１５）；Ｐ１６基因和蛋白丢失主要见于Ⅲ级（８５．７％）和Ⅳ级（１００％）脑胶质瘤。结论：本文结果间接提示Ｐ１６基因和蛋白的丢失可能与脑胶质瘤的发生和演化有关。     

P16基因改变与脑胶质瘤生物学特性相关性的研究

目的 研究Ｐ１６基因改变与脑胶质瘤恶性程度分级及肿瘤细胞增殖活性之间的关系。方法 检测４１例不同级别脑胶质瘤标本和７例正常脑组织Ｐ１６基因改变和ＰＣＮＡ蛋白表达情况。结果 实验组Ｐ１６基因缺失和突变２２例（５４％），ｍＲＮＡ和蛋白表达缺失分别为２３例（５６％）和２７例（６６％），三者改变非一对一关系。Ｐ１６基因改变和ＰＣＮＡ指数随脑胶质瘤恶性程度级别增高呈上升趋势（Ｐ〈０．０５）。Ｐ１６基因改变与     

听神经瘤BCL-2蛋白及bcl-2/JH融合基因的研究

目的 评价石蜡包埋听神经瘤组织中ＢＣＬ－２蛋白表达及相关的ｂｃｌ－２（ｍｂｒ）／ＪＨ融合基因改变,以探讨ｂｃｌ－２癌基因在听神经瘤发病中的可能意义。方法 免疫组化检测石蜡包埋组织中ＢＣＬ－２蛋白的表达;提取石蜡包埋组织的ＤＮＡ,ＰＣＲ检测ｂｃｌ－２（ｍｂｒ）／ＪＨ融合基因。结果 本组４０例听神经瘤,ＢＣＬ－２蛋白表达阳性２７例（６７．５％）,ｂｃｌ－２（ｍｂｒ）／ＪＨ融合基因检出阳性１９例（４７．５％）．结论 听神经瘤中存在ＢＣＬ－２蛋白的高表达及ｔ（１４：１８）染色体易位,提示雪旺氏细胞凋亡抑制可能是听神经瘤发病的分子病理基础之一。     

抑癌基因p16蛋白在脑胶质瘤中的缺失及意义

目的 研究ｐ１６蛋白的缺失率与脑胶质瘤性程度的关系。方法 应用ＳＰ免疫级化检测７２例人脑胶质瘤，４个人脑体外恶性胶质瘤细胞系及１０例正常脑组织中抑癌基因ｐ１６蛋白的表达，结果 正常脑组织、Ｉ级、ＩＩ级、ＩＩＩ级、ＩＶ级、ＣＬ中ｐ１６蛋白的缺失率分别为０．１０％，３１．８％，６３．２％，７１．４％，１００％，脑胶质瘤细胞系，高恶度脑胶质瘤（ＷＨＯ，ＩＩＩ级～ＩＶ级）与低恶度脑胶质瘤（ＷＨＯ，Ｉ级～Ｉ级）之间差异显（Ｐ〈０．０５），结论 ｐ１６蛋白的缺失率与脑胶质瘤的汪事分极和恶性程度密切相关，提示ｐ１６基因在脑胶质瘤的发生，发展过程中起重要作用。     

几种小儿神经系疾病白细胞介素Ⅱ受体和自然杀伤细胞的观察

采用间接免疫荧光法对小儿病脑（７４例）、化脑（６６例）及癫痫（５３例）患儿外周血白细胞介素Ⅱ受体（ＩＬ－２Ｒ）及自然杀伤细胞（ＣＤ１６）进行了检测，结果显示：①病例组ＩＬ－２Ｒ和ＣＤ１６均明显高于对照组（Ｐ＜０．０１）；②ＩＬ－２Ｒ在病脑、化脑急性期升高尤为明显，恢复期有所下降，与病情呈正相关（Ｐ＜０．０１和Ｐ＜０．０５）；③ＣＤ１６的改变与ＩＬ－２Ｒ的改变相平行，但在病脑恢复期无明显下降。从而提示病脑、比脑及癫痫患儿均存在免疫功能系乱，ＩＬ－２Ｒ可能是上述疾病时参与免疫应答的重要细胞因子的表达，ＣＤ１ｅ的改变与ＩＬ－２Ｒ的升高有关，对临床病情估计和预后判断有一定意义。     

p53,CerbB—2和PCNA在脑胶质瘤中表达的意义及其 …

目的 研究７６例脑质瘤的ｐ５３ＣｅｒｂＢ－２和ＰＣＮＡ表达意义及其相关性。方法 应用ＳＰ微波免疫组化技术和统计学分析。结果 （１）在７６例脑胶质瘤组织中；ｐ５３，ＣｅｒｂＢ－２和ＰＣＮＡ的阳性表达率分别是４４．７４％（３４／７６），３４．２１％（２６／７６）和８０．２６％（６１／７６）。（２）ｐ５３的表达强度与胶质瘤的组织学类型和恶性程度呈显著正相关（Ｐ〈０．０１）。（３）ｐ５３ＣｅｒｂＢ－２和Ｐ     

脑肿瘤微卫星不稳定性和错配修复基因hMLH1,hMSH2蛋白表？…

目的 检测脑肿瘤微卫星不稳定性（ＭＩＮ）和错配修复（ＭＭＲ）基因蛋白表达的情况。方法 选取１２个微卫星多态性位点,以微卫星序列－ＰＣＲ法和免疫组化技术检测３７例胶质瘤、２４例脑膜瘤及６例神经鞘瘤中ＭＩＮ和ＭＭＲ基因ｈＭＬＨ１、ｈＭＳＨ２蛋白表达。结果 胶质瘤ＭＩＮ发生率为２７％（１０／３７）,脑膜瘤ＭＩＮ阳性率仅为４％（１／２４）,神经鞘瘤未见微卫生ＤＮＡ异常。ＡＢＣ免疫组化染色发现１０例ｈＭＬＨ     

小脑桥脑角肿瘤患者的脑电图分析

目的：研究小脑桥脑角（ＣＰＡ）肿瘤脑电图（ＥＥＧ）特征及其发生机理。方法：１０６例ＣＰＡ肿瘤患者（男４５例，女６１例，１５－６４岁，平均４２．９岁），以８或１３导脑电图仪，按国际１０／２０系统安放电极，进行 ＥＥＧ描记，再分析其结果。结果：ＥＥＧ未见异常４７例（４４．３％）；弥漫性异常１７例（１６．１％），其中轻度１０例，中度３例，重度４例；局灶性异常４２例（３９．６％）。结论：ＣＰＡ肿瘤属良性肿     

儿童恶性脑胶质瘤P53与细胞增殖核抗原表达的预后价值

目的探讨Ｐ５３与细胞增殖核抗原（ＰＣＮＡ）在儿童恶性脑胶质瘤表达的预后价值。方法采用ＡＢＣ免疫组化方法对３３例儿童恶性脑胶质瘤Ｐ５３与ＰＣＮＡ表达进行回顾性研究。结果３３例儿童恶性脑胶质瘤中Ｐ５３表达阳性１５例（４５％），ＰＣＮＡ表达阳性２９例（８８％）。间变性星形细胞瘤、胶质母细胞瘤及髓母细胞瘤Ｐ５３蛋白表达的阳性比例分别为５／１２、９／１６、１／５，肿瘤Ｐ５３蛋白阴性者其细胞增殖活性均较阴性者高（Ｐ＜００５）；ＰＣＮＡ标记指数与肿瘤的恶性程度呈正相关（Ｐｅａｒｓｏｎ列联系数＝０．５６，Ｐ＜００１）。Ｐ５３或ＰＣＮＡ表达阳性者存活率分别显著低于Ｐ５３或ＰＣＮＡ表达阴性者（Ｐ＜００５，Ｐ＜００１）。结论Ｐ５３基因突变以及由此导致的细胞异常增殖与儿童恶性脑胶质瘤的发生和发展有关；ＰＣＮＡ能较好地反映胶质瘤的恶性程度，其表达检测对临床预后判定有重要参考价值。     

脑肿瘤中P53基因突变与突变型P53蛋白表达的研究

采用聚合酶链反应－单链构象多态性（ＰＣＲ－ＳＳＣＰ）法对４１例脑肿瘤进行Ｐ５３基因突变的检测，并与抗突变型Ｐ５３蛋白单抗的免疫组化染色结果相对照，结果显示脑肿瘤中Ｐ５３基因突变率为３４．１％（１４／４１），胶质瘤为２８％（１０／３６）。Ｐ５３基因突变与突变型Ｐ５３蛋白表达具有高度一致性，且二者均与脑肿瘤的分化程度有关。Ｐ５３基因突变及蛋白的表达不仅出现在高恶度胶质瘤及转移癌，而且可出现在低恶度胶质瘤中，表明Ｐ５３基因的突变在脑瘤的发生、发展过程中起重要作用。     

100例脑肿瘤中p53基因突变与P53蛋白积聚的研究

目的:研究不同类型脑肿瘤中的p53基因突变与P53蛋白积聚及其相关性。方法:采用聚合酶链反应-单链构象多态性(PCR-SSCP)分析及免疫组化法检测100例脑肿瘤p53基因突变及蛋白表达。结果:p53基因突变率为11%(11/100),其中高恶度胶质瘤为37.5%(6/16),低恶度胶质瘤4.3%(1/23),脑膜瘤6.9%(2/29),转移瘤40.0%(2/5)。P53蛋白表达阳性率为22%(22/100),其中高恶度胶质瘤为62.5%(10/16),低恶度胶质瘤为26.1%(6/23),脑膜瘤10.3%(3/29),转移瘤60%(3/5);其他肿瘤均未发现p53基因突变或蛋白表达。P53蛋白表达阳性的22例中伴有p53基因突变者11例,多见于高恶度肿瘤。结论:p53基因失活在脑肿瘤恶性进展过程中起重要作用。p53基因突变与P53蛋白积聚相关,但并非唯一因素。     

Expression of pERK and pAKT in pediatric high grade astrocytomas: Correlation with YKL40 and prognostic significance

The Ras signaling pathway, consisting of mitogen‐activated protein kinase (MAPK) and PI3K/AKT signaling, is a prominent oncogenic pathways in adult diffuse gliomas, but few studies have evaluated such pathways in pediatric malignant gliomas. We investigated by immunohistochemistry MAPK and AKT signaling in a series of 28 pediatric high‐grade gliomas (WHO grade III and IV). We sought a possible association of phospho‐ERK (p‐ERK) and phospho‐AKT (p‐AKT) with expression of other proteins involved in the Ras pathway, that is, YKL40, epidermal growth factor receptor (EGFR), EGFR vIII and c‐Met. Moreover we correlated the expression of p‐ERK and p‐AKT with prognosis. No cases showed expression for c‐Met and EGFR, and only one case was positive for EGFR vIII. YKL‐40 protein was expressed in 43% of cases. We detected expression of p‐ERK and p‐AKT in 61% and 57%, respectively, of pediatric high grade gliomas. Statistical analysis comparing the two groups in term of high and low p‐ERK and p‐AKT expression showed a trend toward worse overall survival in patients with high expression of p‐AKT. The activation of ERK and AKT suggest a possible role of this protein in inducing activation of the Ras signaling pathway in pediatric high‐grade gliomas. Moreover high levels of p‐AKT are associated with worse overall survival.     

p16基因CpG岛甲基化与胶质瘤生物学特性的关系

目的：研究p16基因CpG岛甲基化与胶质瘤恶性程度分级及肿瘤细胞增殖活性的关系。方法：应用半巢式甲基化特异性多聚酶链反应（MSP）检测40例不同级别的胶质瘤组织标本中p16基因CpG岛甲基化状态。免疫组化SP法分析肿瘤组织p16蛋白和Ki-67抗原的表达情况。结果：肿瘤组织甲基化发生率为42.5%（17/40）,p16蛋白表达缺失率为72.5%（29/40）,其中55.2%（16/29）缺失与甲基化有关（P=0.0085）。甲基化发生率随胶质瘤恶性程度增加有增高趋势（χ2=11.4288,P=0.0007）。甲基化阳性者中Ki-67抗原增殖指数明显高于甲基化阴性者（P〈0.05）。结论：p16基因CpG岛甲基化导致该基因灭活是胶质细胞恶性增生的主要机制之一。     

脑胶质瘤p16基因CPG岛高甲基化与基因失活的研究

目的探讨脑胶质瘤中p16基因5'端CPG岛高甲基化与该基因失活的相关性.方法应用免疫组化检测50例脑胶质瘤中P16蛋白的表达;应用PCR技术检测脑胶质瘤中p16基因第1、2外显子缺失及第1外显子5'CPG岛高甲基化.结果免疫组化结果显示50例脑胶质瘤组织中27例恶性胶质瘤P16蛋白缺失,23例低级别胶质瘤P16蛋白阳性;9例恶性胶质瘤p16基因纯合性缺失;P16蛋白阴性的恶性胶质瘤中7例显示p16基因CPG岛高甲基化.结论恶性脑胶质瘤中P16蛋白缺失而没有p16基因纯合性缺失,是由于p16基因5'端CPG岛高甲基化后抑制该基因的转录所致.p16基因高甲基化也是该基因失活的重要机制之一.     

胶质瘤中EGFR扩增、过表达及其与肿瘤增殖关系的研究

目的探讨表皮生长因子受体（EGFR）在胶质瘤中扩增、过表达及其在肿瘤增殖中的作用机制。方法应用SP免疫组化法、RT—PCR、Southern印迹法检测6例正常脑组织、50例不同级别胶质瘤及2个体外胶质瘤细胞系中在EGFR蛋白水平、mRNA水平、DNA水平的表达及扩增情况，以及与肿瘤增殖活性的相关性。结果不同级别的胶质瘤中，表达与扩增程度不同，Ⅱ级与Ⅲ、Ⅳ级肿瘤之间比较具有显著性差异：EGFR过表达与Ki-67在胶质瘤中的表达呈正相关．而EGFR过表达与扩增并不一致。结论EGFR过表达与胶质瘤的增殖活性增高有密切相关性，推测EGFR过表达是肿瘤进展中的早期事件而非进展期事件。     

Analysis of p53 gene mutations in low- and high-grade astrocytomas by polymerase chain reaction-assisted single-strand conformation polymorphism and immunohistochemistry

Using polymerase chain reaction-assisted single-strand conformation polymorphism (PCR-SSCP) and immunohistochemical analyses, mutations in the p53 tumor suppressor gene were examined in 19 low-and high-grade gliomas. By PCR-SSCP and nucleotide analyses, p53 gene mutation was seen in 7 gliomas. Out of the 7 mutations, 3 were located at the CpG site of the previously proposed hot-spot codons 248 and 273, 2 were at codons 171 and 214 and the other 2 were in intron 5, 1 at the splice acceptor site and the other in the vicinity of the splice donor site. The latter 4 mutations have not, or only rarely, been observed in gliomas or in other tumors. However, their effect on the structural and functional alteration of the p53 protein was suggested by positive intranuclear p53 immunostaining in neoplastic cells in 3 mutations including the 1 at the splice acceptor site. In connection with glioma grading, the p53 gene mutation was shown to have occurred in both low- and high-grade gliomas, often in most of the neoplastic cells, as suggested by lack of distinct normal bands and ladders in SSCP and direct sequencing, respectively. The absence of recurrence and malignant transformation over a considerably long postoperative time in our low-grade glioma cases suggested that the p53 gene mutation might not be sufficient for the progression from low- to high-grade gliomas. The frequency of detection of mutation was 7/19(37%) by PCR-SSCP, 8/19(42%) by immunohistochemistry and 10/19(53%) by both methods. The results of PCR-SSCP and immunohistochemistry were consistent in 14 cases(73.7%), but not in 5 cases(26.3%). Thus, the use of both methods was recommended to survey the occurrence of p53 gene mutation more accurately.Supported in part by the Fujisawa Foundation     

EZH2 expression in gliomas: Correlation with CDKN2A gene deletion/ p16 loss and MIB‐1 proliferation index

Enhancer of zeste homolog 2 (EZH2) mediated down‐regulation of CDKN2A/p16 has been observed in cell lines as well as in a few carcinomas. However, there is no study correlating EZH2 expression with CDKN2A/p16 status in gliomas. Hence, the present study was conducted to evaluate EZH2 expression in astrocytic and oligodendroglial tumors and correlate with CDKN2A/p16 status as well as MIB‐1 labeling index (LI). Gliomas of all grades (n = 118) were studied using immunohistochemistry to assess EZH2, p16 and MIB‐1 LI and fluorescence in situ hybrization to evaluate CDKN2A gene status. EZH2 expression and CDKN2A homozygous deletion (HD) were both significantly more frequent in high‐grade gliomas (HGG). Further, strong EZH2 expression (LI ≥ 25%) was significantly more common in HGGs without CDKN2A HD (48.7%; 19/39) as compared to cases with deletion (15.8%; 3/19). Loss of p16 expression was noted in 100% and 51.3% of CDKN2A deleted and non‐deleted tumors, respectively. Notably, 80% (16/20) of the CDKN2A non‐deleted HGGs with p16 loss had strong EZH2 expression, in contrast to only 15.8% (3/19) in the deleted group. Loss of p16 expression significantly correlated with MIB‐1 LI, irrespective of EZH2 status. Thus, this study shows that EZH2 expression correlates with tumor grade in both astrocytic and oligodendroglial tumors and hence can be used as a diagnostic marker to differentiate between low and HGGs. Further, this is the first report demonstrating an inverse correlation of strong EZH2 expression with CDKN2A HD in HGGs. Loss of p16 protein expression is mostly attributable to CDKN2A HD and correlates significantly with MIB‐1 LI. Notably, our study for the first time suggests a possible epigenetic mechanism of p16 loss in CDKN2A non‐deleted HGGs mediated by strong EZH2 expression. A hypothetical model for control of proliferative activity in low versus HGGs is therefore proposed.     

Histopathological-molecular genetic correlations in referral pathologist-diagnosed low-grade "oligodendroglioma"

Allelic loss of chromosome 1p predicts increased chemosensitivity and better survival in oligodendroglial tumors. Clinical testing for 1p loss in oligodendroglial tumors at our hospital has allowed us to postulate that certain histological appearances are associated with 1p allelic status. Forty-four cases received for genetic testing were diagnosed by referring pathologists as pure low-grade oligodendroglioma. Central neuropathological review divided the series equally into 22 cases with classical oligodendroglioma histology and 22 with more astrocytic features. Molecular genetic analyses demonstrated 1p loss in 19 of 22 classic oligodendrogliomas (86%) and maintenance of both 1p alleles in 16 of 22 gliomas with astrocytic features (73%). No glial fibrillary acidic protein-positive cell type (gliofibrillary oligodendrocyte, minigemistocyte, cellular processes) was associated with 1p allelic status. Fourteen of the 44 cases were treated with chemotherapy at tumor progression: 3 "astrocytic" gliomas with 1p loss responded to PCV chemotherapy and 2 classic oligodendrogliomas that maintained both 1p alleles included a responder and a non-responder. These results suggest that histological appearance correctly predicts genotype in approximately 80% of low-grade gliomas, but that tumor genotype more closely predicts chemosensitivity. As a result, such objective molecular genetic analyses should be incorporated into patient management and into clinical trials of low-grade diffuse gliomas.     

MYB upregulation and genetic aberrations in a subset of pediatric low-grade gliomas

Recent studies of genetic abnormalities in pediatric low-grade gliomas (LGGs) have focused on activation of the ERK/MAPK pathway by KIAA1549-BRAF gene fusions in the majority of pilocytic astrocytomas (PAs) and by rare mutations in elements of the pathway across histopathologically diverse LGGs. This study reports that MYB, an oncogene not previously implicated in gliomagenesis, is activated in a diverse subset of pediatric LGGs. The study cohort comprised 57 pediatric LGGs and a comparative cohort of 59 pediatric high-grade gliomas (HGGs). The LGG cohort included 34 PAs and 23 diffuse gliomas; fibrillary astrocytomas (n = 14), oligodendroglial tumors (n = 7), and angiocentric gliomas (n = 2). MYB copy number abnormalities were disclosed using Affymetrix 6.0 SNP arrays and confirmed using interphase fluorescence in situ hybridization. Novel MYB amplifications that upregulate MYB RNA and protein expression were demonstrated in 2/14 diffuse astrocytomas. In addition, focal deletion of the terminal region of MYB was seen in 1 of 2 angiocentric gliomas (AGs). Increased expression of MYB was demonstrated by quantitative RT-PCR and immunohistochemistry. MYB upregulation at the protein level was demonstrated in a proportion of diffuse LGGs (60%), pilocytic astrocytomas (41%), and HGGs (19%), but abnormalities at the genomic level were only a feature of diffuse gliomas. Our data suggest that MYB may have a role in a subset of pediatric gliomas, through a variety of mechanisms in addition to MYB amplification and deletion.